Thetis class frigatehttp://en.wikipedia.org/wiki/Thetis_class_frigateCrew - 60, Passengers -11. Dimensions: Length 369ft, Beam47ft, Draught20ft. Displacement Full 3,500t Performance:Maximum Continuous Speed20kt. Endurance 8,300nm. Provisions 4 monthsThe frigates are ice-strengthened and are able to proceed through 80cm of solid ice. The hull has an icebreaking bow and stem lines suitable for operations in ice with only one propeller. To minimise ice formation on the superstructure, all winches, capstans, etc. are placed under deck. The allowed amount of icing is 375t.WEAPONS The armament consists of one Oto Melara 76mm Super Rapid main gun, one or two 20mm guns from Oerlikon and depth charge throwers. The Super Rapid gun has a rate of fire of 120 rounds a minute and range of 16km. The fire control system is the Saab Systems 9LV 200 mk3. A FLIR Systems Inc AN/AAQ-22 SAFIRE thermal imaging system is used for surveillance.

StanFlex (also known as STANFLEX or Standard Flex) is a modular mission payload system used by the Kongelige Danske Marine (Royal Danish Navy, KDM).

Originally conceived during the 1980s as a way of replacing several classes of minor war vessel with a single class of multi-role ships, the StanFlex system consists of weapons and equipment mounted in standardised containers, which can be loaded into slots on the ships. These containers can be swapped out in a short period of time, allowing the ship to switch between roles when needed.

The success of the modular payload system led the KDM to design all new warships with StanFlex slots, and to install slots on older vessels during major refits. By 2012, nine ship classes capable of carrying StanFlex payloads will be in service.http://en.wikipedia.org/wiki/Stanflex

A patrol boat is a small naval vessel generally designed for coastal defense duties.

There have been many designs for patrol boats. They may be operated by a nation's navy, coast guard, or police force, and may be intended for marine (blue water) and/or estuarine or river ("brown water") environments. They are commonly found engaged in various border protection roles, including anti-smuggling, anti-piracy, fisheries patrols, and immigration law enforcement. They are also often called upon to participate in rescue operations.

They may be broadly classified as Inshore Patrol Vessels (IPVs) and Offshore Patrol Vessels (OPVs).

They are warships typically smaller in size than a corvette and can include fast attack craft, torpedo boats and missile boats, although some are as large as a frigate. The offshore patrol vessels are usually the smallest ship in a navy's fleet that are large and seaworthy enough to patrol off-shore in the open ocean. In larger militaries, such as in the United States military, offshore patrol vessels usually serve in the coast guard, but many smaller nations navies operate these type of ships.

During both World Wars in order to rapidly build up numbers, all sides created auxiliary patrol boats by arming motorboats and sea going fishing trawlers with machine guns and obsolescent naval weapons. Some modern patrol vessels are still based on fishing and leisure boats.

Seagoing patrol boats are typically around 30m (100 ft) in length and usually carry a single medium caliber artillery gun as main armament, and a variety of lighter secondary armament such as machine guns or a close-in weapon system. Depending on role, vessels in this class may also have more sophisticated sensors and fire control systems that would enable them to carry torpedoes, anti-ship and surface-to-air missiles. Most modern designs are powered by gas turbine arrangements such as CODAG, and speeds are generally in the 25–30 knot range. They are primarily used for patrol in a country's Exclusive Economic Zone. Common tasks are fisheries inspection, anti-smuggling (usually anti-narcotics) duties, illegal immigration patrols, anti-piracy patrols and search and rescue (law enforcement-type of work). The largest OPVs might also have a flight deck and helicopter embarked. In times of crisis or war, these vessels are expected to support the larger vessels in the navy.

Their small size and relatively low cost make them one of the most common type of warship in the world. Almost all navies operate at least a few offshore patrol vessels, especially those with only "green water" capabilities. They are useful in smaller seas such as the North Sea as well as in open oceans.

Similar vessels for exclusively military duties include torpedo boats and missile boats. The United States Navy operated the Pegasus class of armed hydrofoils for years, in a patrol boat role.

Project Protector fleet requirements were outlined in the 2002 Maritime Forces Review, conducted by Defence in close cooperation with MFAT, the Ministry of Fisheries, Customs, Treasury, the Maritime Safety Authority, and Police among others. In mid-2004 a study was undertaken in conjunction with the Civilian Agencies to decide the number of vessels and fleet mix necessary.

The Project Protector vessels' capabilities include sealift, coastal and offshore patrol, and at-sea training for the RNZN. New Zealand's approach to the Protector ships, that they are designed, built and maintained to commercial standards, is consistent with other contemporary navies.In April 2004, the Australian firm Tenix Defence Pty Ltd was chosen as the prime contractor for the Project Protector patrol vessels and multi-role vessel for the RNZN. On Thursday 29 July 2004 the Minister of Defence signed the contract with Tenix and they began the final detailed design phase for the new ships before the first steel was cut early in 2005. http://www.navy.mil.nz/visit-the-fleet/ ... efault.htm

Offshore patrol vessels (OPVs) cannot be placed into a single category defined by a specific role or mission; they can range in size from coastal patrol boats or large fast attack craft (about 500 tons) up to corvette or frigate-sized ships (2,500 tons).

Navies and coastguards use OPVs to suit specific needs that depend on the size of the service and the location of the country, as well as the political climate of the region in which the vessels operate.

Drivers for the procurement of OPVs include cost, as small countries with limited naval budgets generally cannot afford larger warships; the need to demonstrate a maritime presence, protect resources and enforce a state's maritime laws; and requirements for managing increasingly large coastal sovereign zones.

In 1967, a state's jurisdiction over the sea was increased from 3 n miles to sovereign territory extending to 12 n miles - an area in which the coastal state is responsible for all activities under and on the water. This was extended in 1994, when regulations governing a 200 n mile exclusive economic zone (EEZ) came into force with the approval of the 1982 United Nations Convention on the Law of the Sea (UNCLOS). Part V of UNCLOS grants the state sovereign rights over the seabed, its subsoil and the water adjacent to the seabed within the 200 n mile limit.

Negotiations are taking place that could see the influence of coastal states extended beyond the 200 n miles of EEZs. Part VI of UNCLOS concerns a coastal state's continental shelf out to 350 n miles from the coastline.

In 2007, Ireland became the first country to gain approval for the extension of its continental shelf, to the west of the island, and now has responsibility for an area of some 141,000 sq n miles - an increase of 100 per cent. The Irish Naval Service has found itself with insufficient ships with which to police this zone. Dublin has put out requirements for two80-90 m-long OPVs and a single 130-140 m-long extended patrol vessel (EPV). The new patrol vessels must have a range of 6,000-8,500 n miles and not only undertake patrolling duties but also fishery protection, search and rescue (SAR), maritime protection, drug interdiction, anti-pollution and vessel boardings. The EPV must also have space for an embarked force of troops and vehicles.

With the gradual expansion of sovereign oceanic territory over the past 40 years, naval forces have been procuring ships that not only provide general law enforcement and SAR capabilities, but also pollution control, firefighting and towing services. Larger warships are not suited to the management of EEZs, so to fill the gap between the smaller coast-hugging patrol craft and the larger ocean-capable warship, OPVs are becoming important assets that are increasing in demand across the globe.

Role-playDavid Bricknell, director of systems and naval product strategy at Rolls-Royce, told Jane's that he believes there are two main types of OPV: combat OPVs and niche capability OPVs. Combat OPVs are designed to provide a small but well-equipped warfighting vessel as a substitute for a larger ship such as a frigate or corvette. These OPVs can reach higher speeds and are often fitted with anti-submarine warfare (ASW), anti-air warfare (AAW) and anti-surface warfare (ASuW) weapon systems, and are designed for rapid response and to take part in battles if required. Designed to naval standards, this type of ship meets all of the necessary survivability standards associated with a warship.

Countries that procure OPVs designed for combat operations are largely located in or near the Middle East or Southeast Asia, according to Bricknell. Sea conditions are generally relatively calm in these regions, where maritime security takes priority over other naval missions near 'pinch points' and areas of tension.

In other parts of the world, OPV designs reflect requirements for sovereignty enforcement of national interests particularly associated with the EEZ area cover fishing and mineral rights, law enforcement patrols and an Arctic or Antarctic ice capability; hydrographic, research and survey work; and disaster response.

Bricknell said that niche OPVs are larger and designed for endurance rather than speed, have the ability to operate in high Sea State conditions and, although armaments can be added to these ships, they provide a naval capability for "presence" missions and "are not equipped to fight battles".

Built to commercial standards and equipped with fewer armaments, niche OPVs are cheaper than their combat counterparts and can be operated with fewer crew members. Designed with a heavy helicopter capability, they can undertake most EEZ activities, but these are secondary to the specific role for which they are designed.

One of the main changes in OPV design relates to the "increasing interest" in the Arctic and Antarctic regions, where "endurance and presence" is important, Bricknell said. Standard OPV designs "do not have this strength" and he expects that some future niche capability presence OPVs will be expected to operate in "mixed ice conditions in and amongst broken ice".

Melting of the polar ice caps has allowed greater access to the Arctic region and raised hopes of securing oil, gas, diamond and uranium resources, and fish stocks. It could also lead to the opening of the Northwest Passage, which could result in significant changes in world maritime trading patterns. Interest in the region follows territorial disputes relating to Part VI of UNCLOS between the Arctic states (Canada, Denmark, Norway, Russia and the United States), which have each submitted claims to the UN to extend their continental shelf.

Canada's naval assets are not able to operate effectively in the Arctic, so requirements were announced on 9 July 2007 for a new class of up to eight Polar Class 5 Arctic/OPVs (A/OPVs) in a CAD3.1 billion (USD2.7 billion) programme. Requirements for the A/OPVs include an endurance of up to four months near the Arctic ice pack in conditions up to Sea State 7.

The ships will be armed and capable of embarking the new CH-148 Cyclone maritime helicopter. With a top speed of 20 kt, the A/OPVs will have steel reinforced hulls designed to plough through year-old ice fields up to 1 m thick, as well as pockets of older, thicker ice. Bricknell believes the A/OPV project will be "fairly commercial" in nature to keep costs down, rather than including too many expensive naval capabilities.

The Norwegian Coast Guard's KV Svalbard, an Arctic-class ship, is one example as is the Rolls-Royce designed Danish Arctic patrol ship, the Knud Rasmussen class. Rolls-Royce designed the Norwegian vessel KV Harstad, a 3,200 ton Ulstein UT 512-class salvage and rescue tug, bought in July 2008, with similar requirements in mind and two similar ships, UT 512Ls, which are currently under construction for Iceland. According to Rolls-Royce, the83 m-long Harstad is equipped for patrolling, pollution control, and outfitted with oil-spill control equipment and fast boarding/rescue boats.

At the opposite end of the scale to presence OPVs are combat vessels such as the United Arab Emirates' (UAE's) Baynunah-class vessels, which are being built by local shipbuilder Abu Dhabi Ship Building (ADSB). Located near the strategic chokepoint of the Strait of Hormuz, the UAE has an acute understanding of naval security. Its requirements are for a multirole combatant for patrolling UAE territorial waters and the EEZ with an AAW and ASuW capability, for the protection of critical assets and commercial shipping in the Persian Gulf.

Despite displacing just 630 tons, ADSB classes the OPVs as corvettes. The ships are equipped with a considerable number of weapon systems including the MBDA Exocet MM40 Block 3 surface-to-surface missile (SSM) and the Raytheon Evolved SeaSparrow Missile (ESSM) RIM-162 surface-to-air missile (SAM).

The Baynunah class is also fitted with an Oto Melara 76 mm gun and two 27 mm cannon. With four MTU 12V 595 TE 90 diesel engines powering three Kamewa waterjets (two driving a single steering waterjet with the remaining two each driving a booster waterjet), the vessels will be able to achieve a maximum speed of 32 kt. The ships also have an organic helicopter capability, mine-avoidance sonar system, MASS decoy system, 3-D radar and a full communications suite.

Mike Stamford, director of sales at ADSB, told Jane's that many types of vessels can be categorised as OPVs, or even ocean-capable patrol vessels (OCPVs). Not only has the term started to encompass more types of ship, but whether to use the term or not depends on the political situation the navy in question faces.

"Often the term OPV is used as a political expedient as OPVs are perceived to be more passive and defensive, whereas the terms corvette, frigate or destroyer are perceived to be overtly offensive and aggressive.

"It is not surprising that some OPVs are multirole and heavily armed, lighter scantling and faster, whereas others are larger, heavier, therefore slower, and equipped for the purposes of survey [and] pollution control. I think in the past some of the vessels which now come under the banner of OPV would have previously been called something else, such as corvette, light frigate or fishery protection vessel, but due to the current fad they fall under the generic term of OPV."

Gulf patrolUK-based BVT Surface Fleet is building both combat OPVs for the Royal Navy of Oman (RNO) and presence OPVs for the Trinidad and Tobago Coast Guard. Under Oman's Project Khareef, BVT is building three new OPVs for the RNO - the first of which is due to launch in 2009. Oman has selected the Exocet anti-ship missile and Mica vertical-launch close-area air-defence systems, and at 98.5 m in length and displacing 2,500 tons, the Khareef-class corvettes are much larger than the UAE's Baynunah OPVs, although their weapons capabilities are similar. The location of Oman and the size of the EEZ mean that their ships require an ocean-going capability. Larger size means the ships will have better seakeeping qualities and longer endurance of more than 4,500 n miles.

The three presence OPVs being builtby BVT for the Trinidad and Tobago Coast Guard will meet a requirement for protection of oil and gas reserves located near the coastlineof the Caribbean islands, as well asfor fishery protection and anti-drug operations.

Production of Ship 02 started in mid-2008, with handover expected in early 2010, and construction of Ship 03 is due to start in early 2009 for a handover scheduled for late 2010. At 90.5 m in length and displacing about 2,000 tons, the OPVs are designed to reach a maximum speed of 25 kt and achieve an endurance of 5,000 n miles at 12 kt. The OPVs can accommodate a crew of 70, but are capable of being operated by 34 personnel with dormitory space for a further 50 troops. Each vessel will carry a high-speed interceptor craft and be fitted with a 20 m-long flight deck for helicopter deployment. In addition, a 16 tonne capacity crane will be fitted to enable the load and offload of cargo in port.

Tim Yarker, export sales director at BVT, told Jane's that the Trinidad and Tobago OPVs represent a "significant increase" in the country's operational capability, as the ships "can carry out regional security tasks and delivery of humanitarian assistance in a hurricane zone". He added that this is also the case with the RNO, where procurement of the Project Khareef corvettes is a "scaling up" of the navy, as the ships will provide new capabilities.

"There is no definition of an OPV ... OPVs are all things to all men," Yarker said. The existence of so many such vessels suggests that each customer appears to have a different set of procurement criteria. Endurance or presence OPVs usually have fewer survivability features, such as reduced shock standards or duplicity of systems.

Yarker said that if this kind of ship gets into a "serious fight ... its role is finished" - the ship is naturally not likely to be able to sustain damage inflicted by a stronger adversary. However, if the job of the OPV "is not to get in the way of the enemy", survivability characteristics are not so important, Yarker explained.

Each country faces a unique set of circumstances that influences OPV procurement decisions, Yarker believes. He added that the OPV market has not increased in size as "the only people that have come into the OPV market that were not there before are the New Zealanders and the Dutch, who have accepted a capability reduction in their fleet".

In September 2003, the Netherlands decided to reduce the capability of its navy and set in motion the sale of four Karel Doorman M-class frigates, intending to replace them with smaller patrol vessels. Dutch shipbuilder Schelde Naval Shipbuilding was contracted in December 2007 to build four OPVs for the Royal Netherlands Navy under Project Patrouilleschepen that are due to enter into service from 2011-13.

The ships will be equipped with fewer combat systems than their predecessors and have been designed for patrol, surveillance and interdiction operations in the Netherlands EEZ, Netherlands Antilles and Aruba. According to Schelde, the new patrol ships will be 108 m long and displace some 3,750 tonnes, which would make them larger than the 3,320 ton frigates they replace.

The ships will have a maximum speed of 21.5 kt and will support expeditionary forces ashore with space for an NH90 helicopter, two 12 m rigid-hulled inflatable boats (RHIBs) and one fast rescue boat. Armaments include a single 76 mm gun, a 20-30 mm gun and two machine guns. The vessels will be built to commercial standards, but will feature added ballistic protection and a gas citadel. Crewed by 50 personnel, the patrol ships will have additional accommodation for 40 people and space for 100 evacuees.

Lean machineSchelde owner Damen has divided the construction of the four ships equally between Schelde's facilities at Vlissingen in the Netherlands and the Galati shipyard in Romania. The ships are halfway through the detailed engineering stage and steel-cutting began in both Galati and Vlissingen in August 2008, with the keel laying for the first ship anticipated in November.

Leon Goossens, manager of product development at Schelde, told Jane's that the development of OPVs will include more high-speed interceptors for boarding operations and drug-trafficking interdictions. Goossens believes the development of "the integrated single-mast configuration in top-side designs will continue not only for the larger OPVs and frigates, but also for the smaller coastal or littoral patrol vessels".

"Electrical propulsion will be adopted on patrol vessels for cruising speed as auxiliary propulsion and in the future also for main propulsion with multiple generating sets, possibly adopting a battery concept for power supply from different kinds of modular energy sources."

A reduction in crew size can be achieved through increased levels of automation in both the platform and combat systems, and through the reduced onboard maintenance needed on modular equipment and systems. Goossens said that modularity principles will be applied to a ship's configuration to a higher degree to allow for increased commonality and the exchange of systems between ships - even between those of different sizes - as well as to facilitate the upgrade process.

The Damen Group has been contracted to build three emergency response vessels for the Swedish Coast Guard. These patrol vessels are specifically designed as multipurpose vessels for normal coastguard duties along the major shipping lanes from St Petersburg, the Baltic Sea and into the North Sea, but also with capabilities for emergency response activities.

The first two ships were contracted on 21 December 2005, with a third vessel with chemical recovery capabilities contracted in April 2007. The 81 m-long vessels have Ice Class 1AS capabilities, but are not intended as ice breakers. They are capable of carrying out rescue operations; firefighting; towing; oil containment, with 600 m of ocean boom; oil recovery (capacity of about 400 tons of crude oil per hour); lighterage of crude oil; remotely operated vehicle operations; and bottle diving support operations. The vessels are also equipped with two fast patrol boats and a heavy crane for recovery duties.

Schelde said the first ship, KBV 001, is nearing completion and will commence trials in November 2008, with delivery expected in December or early January 2009. KBV 002 has been launched and delivery will take place five months after KBV 001. The third ship, KBV 003, is still under construction. KBV 001 is due to commission in the first quarter of 2009, with KBV 003 expected to commission by the end of the same year.

German shipbuilder ThyssenKrupp Marine Systems (TKMS) has also turned its attention to the OPV sector. Jonathan Kamerman, managing director of TKMS International, told Jane's that most OPVs can do 90 per cent of the routine or non-combatant tasks of a frigate. Kamerman believes that in recent years the shift in the security paradigm at sea from high-symmetric threats (short duration, high intensity) to asymmetric threats (sustained, low intensity) has meant that ship requirements have gone "from complex platforms, complex C3 [command, control and communications], sensors and effectors, [and] high cost, to simple platforms, basic combat systems and low cost".

Bridging platformMany naval forces have high-end frigate-sized ships and low-end small patrol ships, but nothing to fill the capability gap in between. "That is where OPVs come in," said Kamerman. As maritime mission requirements move away from civilian missions such as humanitarian, SAR, firefighting and environmental protection, towards naval missions such as counter-terrorism, crisis response, special operations and combat, "costs increase as task and platform complexity go up", said Kamerman.

Managing the right force balance, so that a navy does not have to resort to using large warships for fisheries patrol or end up with ships too small to operate in an EEZ, is about achieving "mission sufficiency", said Kamerman. Navies should choose a low-cost ship with a limited mission-defined combat suite that can carry out both civilian and some lower-order naval tasks, he added.

According to Kamerman, the "sufficient vessel" is a simple, robust platform playing the mothership role to fast interceptor boats and a helicopter. These assets would be deployed for surveillance, interdiction, boarding, inspections, arrest and seizure, special forces insertion and shallow-water access and mobility. The ship should be equipped with tactical networking and an onboard special forces or marine contingent. The reaction time and tactical mobility of the ship should be defined not by the ship itself but by its assets (i.e. the vessel systems).

To achieve a cost-effective platform, Kamerman warns that navies must avoid the traditional cost drivers. He said that OPVs should use commercial design and build standards, and retain a modest speed requirement of "between 19 to 23 kt". The use of TEU container payloads is another way of increasing capability cheaply. OPVs do not need stealth characteristics as this would "reduce operability", Kamerman said.

It is the application of combat systems and sensors that represent the biggest potential cost increases. The combat system has to be mission-defined and limited to the low-intensity capabilities required to prevent cost and mission growth. However, good communications systems are paramount and should not be skimped on. Basic C2 (for an adequate surface tactical picture), navigation and 2-D search radar systems should be applied, "but nothing more than that", said Kamerman. Equipment for real-time threat analysis or weapons assignment is not required on an OPV, which should instead rely on electro-optical (EO) sensors as the "primary sensors".

For weapons fit, a 20-40 mm cannon and some 12.7 mm machine guns will suffice, but the addition of larger guns, missiles or sensors, such as a 3-D radar or sophisticated anti-air fire-control systems, would push the ship into the more expensive high-end combat realm. Sticking to these principles does not mean that a ship cannot have good growth potential. Space and weight can be provided for systems that have not actually been fitted, allowing for future flexibility - as in the case of the large Dutch OPVs.

Kamerman said the OPV must have good seakeeping up to at least Sea State 5 to allow for the operation of a helicopter and fast boats. OPVs should generally be short and fat, and while this means the vessels will be slow, they will provide stability and increased interior volume. For stability OPVs should have active fin stabilisers, bilge keels, a bulbous bow, wet deck inhibitors, and good freeboard for deck wetness reduction as well as lee creation for boat operations.

Launch padOPVs that are longer and thinner can achieve faster speeds, but are less stable and cannot safely operate a helicopter in conditions above Sea State 3 or 4. Kamerman believes OPVs must be optimised to support the launch and recovery of helicopter and boat assets. A large helicopter deck with stores space, to support a 12 tonne transport helicopter with hover in-flight refuelling, and the ability for day and night operations, should be a key OPV requirement. For boat operations, the OPV should be equipped with two (or preferably four) large RHIBs (of more than 9 m in length) with large work spaces, capability for low-speed manoeuvrability, single self-compensating lifting point gantry davits and a boat loading crane.

TKMS has developed a series of four central designs of 1,000-2,000 ton OPVs reflecting these specifications: a 67 m fast OPV; an 81 m Guardian-class OPV displacing about 1,800 tons; an 85 m, 1,900 ton Sentinel-class multimission OPV; and a larger 99 m version of the Sentinel OPV displacing 2,100 tons, all with the same 13.9 m beam standardising the hull form. Built to commercial standards, the vessels are equipped with a helicopter and boat capability, modest speed, sensors and weapons equipment; they are short and fat, for good seakeeping, and with growth potential for future equipment installations.

Spanish shipbuilder Navantia is also adhering to these principles for the construction of the first four Buque de Acción Maritima patrol ships for the Spanish Navy at its yard in Ferrol. Up to eight ships will be built to a modular design for low-intensity operations: counter-terrorism patrolling; protection of maritime resources; maritime interdiction; and port security.

Displacing 2,500 tons, the ships are lightly armed with a single Oto Melara 76 mm gun and two 20 mm cannon, and fitted with the SCOMBA combat management system (CMS), but are capable of launching a helicopter (with a hangar for an NH90-sized aircraft) and are to be equipped with two RHIBs. They will be equipped with a crane, space will be provided for three standard containers and there will be plenty of additional space for operations, crew and working areas.

A spokeswoman for Navantia told Jane's: "The strict control of the naval budgets has forced the main world navies to get this type of vessel, as they are smaller ships orientated to maritime security and to patrol in economic exclusive waters in order to control national safety. But also demand has grown in order to control terrorism, drugs and immigration."

Navantia estimates that about 200 units will be built over the next few years, ranging from 500-2,500 tonnes. The main trend identified in the OPV market is the "tendency in these ships for more automation and reduction of crew [to] about 40 people and this allows a considerable saving of budget".

The company also started production of the first of four 2,419 ton POVZEE (Patrullero Oceánico para la Vigilancia de la Zona Económica Exclusiva) ocean patrol ships for the Venezuelan Navy at its Puerto Real yard near Cadiz on 11 September. Deliveries are scheduled for May 2010, September 2010, February 2011 and July 2011 respectively.

The 98.9 m-long ships will be used for EEZ protection duties, but have the propulsion and weapons for a much wider-ranging role including maritime security, surveillance, law enforcement, SAR, pollution control and humanitarian relief missions. Each vessel will have four 4,400 kW MTU 12V 1163 TB93 diesels and twin shafts with variable-pitch propellers, giving a maximum speed of 24 kt and endurance of 3,500 n miles at 18 kt. The POVZEE ships will be equipped with a 76 mm gun and a 35 mm gun, with Thales providing the Tacticos CMS, Sting optronic director, Mirador trainable EO observation system and SMART-S 3-D air/surface-search radar. POVZEE will have a flight deck and hangar for day/night helicopter operations and two semi-rigid launch boats.

Argentina is seeking to build five 80 m-long OPVs to a proven design at its Río Santiago yard under the Patrulleros de Alta Mar programme. The ships are intended to range from 1,500-1,800 tons and be equipped with a 40-76 mm gun, but the invitation of bids was delayed, causing the Argentine Navy to join forces with the Chilean Navy to procure five vessels based on the same machinery and systems.

Chilean naval programmes have proved to be more successful, with the commissioning of the first of two Proyecto Danubio IV OPVs, Piloto Pardo, in June 2008. Built by ASMAR at its Talcahuno yard to an 80 m Fassmer design, the ships are powered by twin Wärtsilä 12V 26 diesel engines for a speed of 20 kt and with the capability to embark a medium helicopter and two 7 m Pumar RHIBs. Armed with a single 40 mm naval gun mount, there is space for a 76 mm gun if required. The second ship, Policarpo Toro, was launched in October and is due to be delivered in mid-2009.

Brazil plans to acquire 11 OPVs from 2009-25, but funding problems have led to delays. In September 2006, an order for two NAPA 500-class 477 ton vessels based on CMN Group's Vigilante 400 CL 54 design was approved. Built by local manufacturer INACE at Fortaleza, the two ships are due for delivery in 2009, with a class of eight ships planned (orders for a further four have been approved). However, Brazil still has a requirement for ocean-capable vessels displacing about 2,000 tons, like those being acquired by Argentina and Chile.

Future capabilityGoa Shipyard Limited in India has been contracted to build a series of 105 m-long, 2,215 ton OPVs for the Indian Navy. The ships are based on the Indian Coast Guard's advanced OPV ICGS Sankalp, which was launched in April 2006. Construction of the first of the new OPVs began in 2007, with first deliveries expected in 2009-10. Three vessels had been laid down by May 2008 - with plans for a fourth ship - each worth between USD80 million and USD120 million. They will be armed with a 76 mm naval gun and two 30 mm cannon, and will be capable of operating a single Hindustan Aeronautics Limited (HAL) Dhruv helicopter.

In addition to three light frigates ordered from Schelde and a FREMM frigate from French shipbuilder DCNS, the Royal Moroccan Navy is set to update its patrol ship fleet with the procurement of four 70 m-long OPVs from Raidco Marine and Aker Yards (as subcontractor for hull construction). Equipped with a 76 mm gun and 40 mm cannon, the ships will carry out surveillance and fishery control operations in Morocco's EEZ. The decision was confirmed by Raidco Director Jean-Michel Monnier in late May, with delivery of the vessels due to begin in 2010. The ship's unit cost is expected to be about USD30-40 million.

The French Navy maintains a sizeable fleet of patrol and support vessels that regularly deploy to French Overseas Departments and Territories. In September 2008, senior officials reiterated the need for a new class of vessels to replace the nine D'Estienne d'Orves-class (Type A 69) 1,300 ton patrol frigates, 10 P400-class patrol ships and support ships over the next decade.

The new-generation patrol vessels will replace the P400 patrol ships, which will reach the end of their service lives from 2010 onwards. However, the programme schedule is not yet defined and the nature of the replacement vessels is uncertain, possibly involving units larger than the current 477 ton displacement P400.

The replacement support vessels, dubbed bâtiment d'intervention et de souveraineté (intervention and sovereignty vessels), will be capable of transporting and supporting a company-strength (120) troop detachment with up to 20 vehicles, weapons and equipment. Rolls-Royce intends to offer a variant of its UT offshore support vessel. The programme has not yet entered a preliminary phase or been included in budget planning. Both projects may be combined into a single programme for up to 20 units.

As a part of its Future Surface Combatant (FSC) programme to recapitalise the UK Royal Navy surface fleet, the UK Ministry of Defence will replace ageing patrol ships and minehunters with a single class of eight 2,000 ton multimission ocean-capable patrol ships (designated C3 - the third type of ship to be procured under FSC). The ships will undertake maritime security, special, mine countermeasures and interdiction operations. C3 funding is being separated from the rest of FSC and tied to the Future Mine Countermeasures capability, as the ships have different drivers to the C1 and C2 components.

For many small navies, procurement of OPVs is a step towards acquiring something bigger. Navies seeking to deploy powerful warships must first become established as a modern, effective force and learn to operate smaller ships.

In other cases, a country may already have an OPV construction capability, and instead seek to purchase designs and systems that meet requirements, while building the hull themselves.